Overview

Technology	Stateless/Stateful	Purpose	Notes
NAT64	Stateful or stateless. Usually deployed statefully.	Allow IPv6-only clients access to the IPv4 internet	DNS64 server required
6in4	Stateless	Allow IPv6 sites to communicate over a shared IPv4-only network using p2p tunnels	IGP adjacency possible due to p2p nature of the tunnel.
6to4	Stateless	6in4 but with p2mp tunnels and dynamically determined tunnel endpoints	Uses 2002:<ipv4 address>::/48. The IPv4 address is embedded in the IPv6 destination address. IGP adjacency not possible due to p2mp nature.
6RD	Stateless	6to4 but without the 2002::/16 prefix requirement.	The full IPv4 address does not need to be mapped if routers share a common subnet.
DS Lite	Stateful	Allow IPv4 customers to traverse an IPv6-only access network. The AFTR device does heavy stateful NAT.	The CPE does no NATing at all. It simply tunnels IPv4 traffic to the AFTR device. IPv6 traffic flows natively.
MAP	Stateless	DS Lite but with NAT on the CPE. The BR is now stateless.	The CPE does NAT with a given set of source ports. This allows multiple separate CPEs to NAT to the same public IPv4 address. IPv6 traffic flows natively.